Let's keep retrying to get remote llog in all cases until the local MDT is being umount or the recovery is aborted.
This is similar as LU-7277, but unfortunately the patch for LU-7277 did not fix all of cases.
LU-7455 Tracking tickets to make DNE pass soak-test.
LU-7277 Keep retry to retrieve remote update log in old_sub_recovery_thread